The present invention is related to the field of apparatus for pumping live fish from one location to another.
In the fish growing industry, it is necessary to transfer live fish from holding tanks or ponds into live carrying tanks on transport vehicles. This process usually involves lifting the fish from the tanks upward to carrying tanks which are usually provided on specially designed trucks. The process has, in the past, been performed by workers with nets. This is a relatively safe manner in transferring the fish. Relatively few fish are injured by the net or in transfer from the net to the holding tank; however, efficiency is lost in manpower since it usually takes several workers several hours to load a single truck. It therefore becomes desirable to obtain some form of pump that will move live fish from their stationary holding tanks or ponds to the tanks on transport vehicles in an efficient manner with minimal injury to the fish.
Apparatus for pumping fish is not new per se. Fish pumps have been utilized in the salt water industry for some time. However, the pumps utilized there are not usually designed to prevent damage to the fish being pumped since it is unnecessary that the fish remain alive until they reach their destination point. When fresh water fish such as trout are harvested, it is very desirable to keep the fish alive until they reach their destination to keep the meat as fresh as possible.
It is a first object of the present invention to provide a fish pump that will operate efficiently in pumping fish in water from one location to another without injuring the fish either by battering against the rotor or by bending the fish to an overall length that is less than half the straightened length of the fish.
Another object is to provide such a pump that makes use of a mixed flow form of rotor wherein both axial and centrifugal force components are imparted to the fluid moving through the pump whereby a somewhat greater "head" may be realized at a relatively low rpm.
A still further object is to provide such a pump that includes a mixed flow rotor designed such that a vortex is formed upstream of the rotor during operation to initiate alignment of the fish before they enter through the rotor passages. By so aligning the fish, there is considerably less chance that the fish will be struck by the edges of the rotor.
Various other objects and advantages will become apparent upon reading the following description which, when taken with the accompanying drawings, describe a preferred form of my invention. It is to be noted, however, that the following description and drawings are given merely to set forth a preferred form of the invention and that alterations may be made within the scope of the appended claims. Therefore, only the claims are to be taken as specific definitions of what I claim to be my invention.